Complex machinery, such as vehicles (e.g., an automobile, plane, rotorcraft, locomotive, etc.), generators, automated machining tools, etc., include numerous constituent components (e.g., levers, arms, pistons, driveshafts, clutch plates, etc.) that move and are subject to stress and strain during their operating lifetime. Such repeated stress/strain eventually causes a component to fail. To avoid failure during operation of the machinery, numerous approaches can be used.
For example, the component can be manufactured to a sufficient robustness that the stress/strain to which it will be subjected during operation will not cause it to fail in any reasonable time period. However, this approach frequently requires a massive over design of the component, thereby adding mass and size to the component, which reduces the operating efficiency of the machine. As a result, use of this approach is often limited to applications in which the component is extremely expensive to replace, the component absolutely cannot fail, and there is sufficient space and weight available in the machine to accommodate the over designed component.
In other approaches, the component is replaced prior to failure. For example, the component can be replaced at an interval shorter than any possible failure. Typically, this approach is limited to components that are relatively inexpensive to replace. Alternatively, the component can be replaced on a schedule that is determined based on statistical wear and usage. In particular, a history of the machine and the component are examined over many lifetimes to produce a recommended schedule of replacement. However, this approach is limited to machines having a sufficiently long operating history. Additionally, since the approach is statistical, unexpected failure is possible. As a result, a worst-case scenario may be assumed in practical applications, which can result in a component being disposed long before its useful lifetime would have ended. In another approach, one or more models can be used to simulate operational characteristics of the machine and/or component to produce a lifetime use formula. However, since this approach is also statistical, large safety margins are frequently used, which can result in a component being disposed long before its useful lifetime would have ended.
Ideally, a component could be directly monitored and replaced when a selected percentage of its useful lifetime has expired. However, to date, many components have not been effectively instrumented for monitoring due to size constraints and/or operating conditions (e.g., extreme heat, cold, vibration, and/or the like). Additionally, the monitoring instruments frequently require wiring for communication and/or power, which often cannot be included in moving components. However, directly monitoring component(s) remains a desirable goal. For example, such a solution could reduce the time, effort, and material wasted in performing periodic inspections and replacing components that have not reached their useful lifetimes, without compromising the operational functionality or safety of the machine.
Similarly, it is desirable to monitor a “limiting” component of a machine. The limiting component is a component whose operational parameters limits the use of one or more additional components, and therefore limits the performance of the machine. In particular, a maximum amount of stress/strain that a component can withstand may be limited due to space/weight/material constraints of the component. However, a model of the machine may indicate that other component(s) may be able to operate in a manner that would generate an amount of stress/strain on the component that exceeds the maximum amount. In this case, since the actual stress/strain cannot be measured, operation of the other component(s) will be limited to keep the stress/strain induced on the component within safe limits based on the model (and some safety margin).
Electronic and mechanical designs for devices continue to be reduced in size. In recent years, micro-scale engineering has proposed theoretical and experimental designs for these devices, often referred to as Micro-ElectroMechanical Systems (MEMS) and Nano-ElectroMechanical Systems (NEMS). As a result of these designs, some practical applications have begun to emerge on the market in the form of miniature sensors for some limited domains. Approaches for building MEMS devices exist for many challenges currently met by microelectronic devices. For example, microscale steam engines, shutters, mirrors, power systems, and others have been produced, while designs for MEMS solar cells and light-based communications, radio frequency (RF)-related MEMS devices, MEMS power harvesting/generation sources, MEMS memory devices, and others, also have been proposed.
In view of the foregoing, a need exists to overcome one or more of the deficiencies in the related art.